TYC has their tail lights tested to meet all applicable specifications and standards as set forth by the SAE, and all TYC lamps are compliant with federal safety standard FMVSS #108, as administered by the Department of Transportation.

Basically it means it passes all the test that makes a tail light street legal. This includes the brightness at certain angle which is crucial since some altezzas and aftermarket tail light is barely visible or hard to see in bright sunny weather and at night sometimes.